51217812 has 48 divisors (see below), whose sum is σ = 133257600. Its totient is φ = 17012160.

The previous prime is 51217811. The next prime is 51217813. The reversal of 51217812 is 21871215.

It is an interprime number because it is at equal distance from previous prime (51217811) and next prime (51217813).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51217811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38112 + ... + 39432.

It is an arithmetic number, because the mean of its divisors is an integer number (2776200).

Almost surely, 2^51217812 is an apocalyptic number.

It is an amenable number.

51217812 is an abundant number, since it is smaller than the sum of its proper divisors (82039788).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51217812 is a wasteful number, since it uses less digits than its factorization.

51217812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1693 (or 1685 counting only the distinct ones).

The product of its digits is 1120, while the sum is 27.

The square root of 51217812 is about 7156.6620711055. The cubic root of 51217812 is about 371.3701621030.

The spelling of 51217812 in words is "fifty-one million, two hundred seventeen thousand, eight hundred twelve".